Energy-aware routing in mobile ad hoc networks (MANETS)

This paper presents a hybrid routing algorithm, named hybrid energy-aware routing (HEAR), to balance the energy consumption of mobile nodes in a MANET in order to extend their average lifetime. By exchanging periodic "hello" message with direct neighbors to build and maintain a neighbor table, each mobile node can always maintain routes for. neighbors within two hops. By introducing a time delay mechanism into the route discovery phase of on-demand routing, mobile nodes can find energy-rich paths to destinations beyond two hops. By utilizing neighbor table information, local salvage of data packets can be implemented when the downstream node is energy-poor or disconnected. To alleviate the side effect of periodic hello messages on increasing the routing overhead, a mobile node piggybacks its own energy information in outgoing packets. This information can maximally travel two-hops so that the corresponding entry in this mobile node one and two-hop neighbors' neighbor table can be naturally updated without "hello" message. The periodic "hello" of a mobile node may not include all its one-hop neighbors' information but only the information updated since last "hello ". All these mechanisms help to reduce the number and the average size of hello messages. Our proposed algorithm in this paper can avoid using mobile nodes with poor energy level as relaying nodes, eliminate the blocking property of some other energy-balancing routing schemes, and guarantee basic routing performance, such as system throughput and routing overhead.